It is well known for seeders to employ a plurality of trailing arms each of which is provided with a press-wheel for pressing the soil displaced in creating a seed receiving furrow. It is common practice for press-wheels to be fitted with a protective hub cap which covers the end of the stub-axle on which the wheel is rotatably mounted for the purpose of preventing the ingress of dirt, grit etc into the hub of the wheel and in turn the wheel bearings. It is not uncommon for these caps to be dislodged when the machine is in operation. Once dislodged, the journalled end of the stub-axle and the bearings are exposed to contamination and subsequent bearing damage over a period of time. To address this problem, one known press-wheel construction incorporates a central bolt-on over cap which is secured to the outer face of the press-wheel, in the spoke region thereof, by means of a series of bolts. The over cap completely covers the journalled end of the press-wheel axle. The fitment of such an over-cap is very labour intensive and hence uneconomical from a manufacturing point of view.
It is also well known for press-wheels to be fitted with a separate hub and stub-axle arrangement, with the hub flange being fastened directly to the inner side of the press-wheel. The weight of such an assembly, due to the heavy-duty construction of the separate hub, is quite heavy and in situations where a seeder is fitted with a large number of such press-wheels, the additional overall weight of the machine is quite significant. It is desirable therefore for the weight of the press-wheel to be reduced.